Method of making an agricultural disc



Sept. 20, 1960 J. H. INGERSOLL METHOD OF MAKING AN AGRICULTURAL DISC Original Filed Jan. 26, 1956 4 Sheets-Sheet 1 Jams fl fngerzsall Sept. 20, 1960 J. H. INGERSOLL 2,952,895

METHOD OF MAKING AN AGRICULTURAL DISC Original Filed Jan. 26, 1956 4 Sheets-Sheet 2 fn z/eni ar" Ja 77165 ff [77 967150 [Z Sept. 20, 1960 J. H. INGERSOLL 2,952,395

I METHOD OF MAKING AN AGRICULTURAL DISC Original Filed Jan. 26, 1956 45heets-Sheet 3 Jamsff/rz 6715011 Sept. 20, 1960 J. H. INGERSOLL 2,952,895

METHOD OF MAKING AN AGRICULTURAL DISC Original Filed Jan. 26, 1955 4 Sheets-Sheet 4 fnuerzibf James/Y frzgensoll a GQJ Unite lVIETHOD OF MAKING AN AGRICULTURAL DISC 8 Claims. (Cl. 29-14) The present invention relates in its broadest aspects to a method of making sheet metal articles and more specifically and improved sheet steel earth working disc particularly applicable to agricultural implements.

This application is a division of the copending application 'of I. H. Ingersoll, Serial No. 561,595, filed January 26, 1956.

For a considerable period of time it has been rather common practice to utilize agricultural implements for working the soil comprising concave sheet steel discs formed with a tapered peripheral region having a ground edge therearound for providing a suitable earth cutting edge'around the disc. The conventional method of manufacturing earth working discs utilizes a grinding operation for'the purpose of providing the relatively sharp periphery of the disc, and this method is not without drawbacks.

When the agricultural discs are peripherally ground to provide the cutting edge therearound, the friction during the grinding operation between the grinding wheel and the "edge of the disc is sufiicient to heat the edge .of the disc-and in many instances this frictional heating actually changes the metallurgical characteristics of the metal around the disc periphery. Because of the fact that the grinding period is not a fixed interval time, and because the actual temperature of the metal at the periphery of the disc is also a function of the thickness of the metal in contact with the grinding wheel, there is usually a temperature gradient from a high value at the sharpest point on the periphery toward the center 'of the disc. .As a result of this temperature gradient, the subsequent cooling, due to what may be termed air quenching, causes a gradient in the hardness of the cutting edges, which is present in a high percentage of earth cutting discs manufactured in a conventional manner.

Quite often the grinding wheels used to sharpen the peripheries of agricultural discs are so rough that they form resultant ridges and valleys along the ground peripheral surface of the discs. Due to this condition stress concentrations are formed which have been known :to cause breakage of the discs when the discs are put into .use. The present invention, by eliminating grinding of the disc edges, therefore'overcomes this inherent drawback of agricultural discs manufactured by conventional methods employing a grinding operation.

The present invention therefore has, as one of itsprincipal objects, the provision of a method for making an earth Working disc which omits there inherent undesirablesteps conventially employed when the cutting edges around the discs are formed by grinding.

-A further object of the present invention is to provide a method for making earth working discs wherein the cutting edges therearound are formed by a single shearingoperation.

More particularly, the present invention contemplates the over-forming of the peripheral region of the disc blanks, shearing the edge of theover-formed blank by a single operation of a pair of complementary die members,

States Patent and the subsequent reshaping of the entire disc blank to impart the desired final curvature to the disc.

It is contemplated that the initial over-forming operationmay be carried out either by complementary edge rollsor by complementary dies.

The above general objects and advantages, as Well as others, will become apparent from the following detailed description when read in conjunction with the accompanying drawingawherein:

Figs. 1-5 schematically represent the method steps of a preferred embodiment of the present invention,'Fig. 1 representing a plan view of a disc blank, Fig. 2 representing the disc blank having the center and locating holes formed therein; Figs. 3 and 3a respectively representing plan and sectional views of the disc blank after the periphery thereof is subjected to an edge rolling operation to provide an initial taperaround the periphery of the blank, Figs. 4 and 4a respectively representing plan and sectional views of the disc blank after it has been subjected to a "die forming operation in order to upset the periphery of the blank and after the blank has been peripherally sheared in order to provide the cutting edge therearound, and Figs. 5 and 5a, respectively, representing the disc after it has been subjected to a reforming operation -to impart the desired curvature thereto;

Fig. 6 is aschematic view illustrating the edge rolling operation on the periphery of the disc to provide a taper on one side thereof;

Fig. 6a is an enlarged fragmentary view of the edge rolling operation shown in Fig. 6;

Fig. 7 is a side elevational view, shown generally in section, of a die arrangement in a press-adaptedto shape the peripheral region of the disc and thereafter shear the outermost periphery of the disc to form a cutting edge therearound;

Fig. 7a is a fragmentary sectional View illustrating .on an enlarged scale, the die members shown in Fig. 7 at .the point in the operation where the peripheral region of the disc has been upset but the shearing dies have, as yet, not performed their function;

Fig. 7b is a fragmentary sectional view similar to Fig. 7a, and illustrating. the position of the shearing dies immediately after the shearing operation has taken place;

Fig. 8 is a sectional .view of a die utilized for the purpose of reforming the disc and imparting the desired final curvature thereto;

Fig. 9 shows an alternative device comprising a pair of edge rolls .for both tapering and upsetting the periphery of the disc;

Fig. 9a is a slightly larger scale fragmentary. detail View of a portion of the rolls of Fig. 9 showing the peripheral region of the disc disposed between the edge rolls; and

Fig. 10 is a fragmentary sectional view of the peripheral region of an earth Working disc having a cutting edge formed thereon by the method of .the present invention;

Fig. ll'is an elevational view of a modified form of die for preforming the periphery of the disc, trimming the periphery thereof and reforming the disc in a single operationalsequence, this view showing the press members in the position immediately after the edge of the disc has been trimmed; and

Fig. 12 is an elevational View, similar to Fig. 11, and showing the die of Fig. '11 at the end of its cycle of operation.

Referring now to the drawings, wherein like reference numerals have been used to identify identical parts in the different Views, and with particular reference to Figs. 1-5, a first or preferred method of forming agricultural discs with a sheared peripheral cutting edge will be described.

In practicing the preferred method comprising the subject matter of the present invention, a substantially circular sheet steel blank of the desired thickness and diameter is formed by any well-known method, such as a punching operation and this circular blank is illustrated in Fig. 1 and designated generally by reference numeral 11. The next method step in the formation of the disc is illustrated in Fig. 2 and comprises the piercing or punching of any desired center hole 12 and any desired bolt holes 13. The holes 12 and 13 may be formed by conventional methods, and it is contemplated that they will be provided as needed.

Fig. 3 represents the method stepcomprising rolling a taper 14 around the periphery ofthe disc. The edge rolling operation illustrated schematically by Figs. 3 and 3a is broughtout more clearly in Figs. 6 and 6a and will be described more completely hereinafter.

Subsequent to the formation of. the taper 14 around the periphery of the disc, the peripheral portion, designated generally by reference, numeral 15, of the disc is shaped so that the outer portion thereof comprises a lip disposed at a substantial angle to the central portion 16' of the disc blank 11. The disc blank 11 is then trimmed around the periphery by a shearing operation to provide acutting edge 17. A final step in the formation of the disc is illustrated in Figs. 5 and 5a and comprises the reshaping of the entire disc blank 11 in order to impart a substantially constant radius of curvature to the disc blank.

The formation of the circular disc blank, as illustrated in Fig. 1, and the piercing of the center hole 12 and locating holes in the circular disc blank 11' are car ried out in a conventional manner and need not be described in any further particularity in the present description. Turning now to Fig. 6, the edge rolling operation illustrated in Figs. 3 and 3a will be described in greater detail. The circular disc blank 11- is mounted for rotation with its center disposed on a vertical axis 18. A pair of edge rollers 19 and 20 are suitably mounted on driving spindles 21 and 22, respectively. The outer periphery 23 of roller 20 is substantially cylindrical whereas the outer periphery 24 of the roller-19 is tapered slightly, as indicated at 25. The two-rollers 19 and 20 are urged towards one another with substantial force and upon rotation of the rollers, with the peripheral portion 15 of the disc blank 11 disposed therebetween, the tapered portion 25 of roller 19 and the outer periphery 23 of the roller 20 function to form a peripheral taper 14 around the periphery of the disc, it being understood that upon rotation of the rollers 19 and 20 the disc blank 11 rotates on axis 18. Y

It will be understood that the edge rolling means is illustrated schematically in Figs. 6 and 6a and'it is not deemed essential to go into any further detail in connection with this method step. 1 7

Turning now to Fig. 7, there is illustrated therein, a die arrangement in a press for die forming the peripheral portion 15 of the disc 11 and for shearing the periphery of the disc 11 at an angle sufiiciently acute to provide the cutting edge 17 around the disc periphery at the juncture between the sheared surface and theunder or concave side of the disc 11. a

The die arrangement located in a press shown in Fig. 7 comprises a substantially stationary base 'or bed plate 26 which supports a structure designated by reference numeral 27. The structure 27 comprises a fixed shearing ring 28 and a fixed shaping or die forming member:29. The shaping member 29 is'secured to the stationary structure 27 by means of suitable bolts 30 and the structure 27 is secured'to the bed plate 26 by means of suitable bolts 31.* H A disc-positioning member '32 is disposed concentrically within the die forming member 29 and comprises .a central portion 33 which may be'p'rovided with any desired indexing mechanism for accurately locating the disc blank 11 with respect to the die forming member 29. The locating member 33 may be secured to the positioning member 32 by bolts 34.

The die shown in Fig. 7 comprises an upper movable member 35 to which is secured a die positioning plate 36. The die positioning plate 36 is formed with suitable shoulders 37 for accurately positioning a ring 38 which is formed in member 36 immediately opposite the openings 41. Heavy duty compression springs 43 are dis posed within openings 41 and 42 and serve to transmit force downwardly from the movable upper press member 35 to the die forming or shaping member 40.

When the upper press member 35 is in its raised position the compression springs 43 function to retain the die forming member 40 in its downward position with shoulders 44 resting on upper die member 39. Thus, upon initial downward'movement of the press member 35 the die forming member 40 moves downwardly and a concavely curved under portion 45 of die forming member 40, in cooperation with a complementary convexly curved die forming portion 46 on the lower die forming member 29, functions to shape the peripheral region or portion 15 of the disc blank 11 to conform to the complementary shaped surfaces on die forming members 40 and 29.

When the downwardmost point of advance of die forming member 40 is reached, the further downward movement of press member 35 causes ring 38 and upper shearing member 39 to progress further downwardly and these two members successively function, as illustrated in Figs. 7a and 7b,'to shear the periphery of the disc blank 11 at a sufficiently acute angle to shear the periphery of the disc blank 11 along a substantially cylindrical sheared surface 47 which intersects the under side 48 of disc 11 at an angle which is sufiiciently acute to form an earth cutting edge around the periphery of the disc.

In one operative embodiment of the structure shown in Fig. 7, the angle of intersection between the sheared surface 47 and the under surface 48 of the disc blank 11 is of the order of magnitude of approximately between 25 and 30.

The peripheral portion of the disc 11, which is trimmed ofi by the mutual cooperation of the complementary shearing members 39 and 28, is designated by reference numeral 49 and forms a ring surrounding the shear member 28. In the operation of the die shown in Fig. 7, after the upper movable member 35 reaches the limit of its downward movement and has completed shaping the peripheral portion 15 of the disc and shearing the peripheral edge of the disc, the upper portion 35 is withdrawn and carries with it all of the associated movable portions of the press. During the cycle of operation a plurality of plungers 5t} automatically rise in order to raise an ejector ring 51 which raises the scrap ring 49 to a position where it can be removed from the press. Similarly, after the movable portion of the press is raised, another group of plungers 52 are actuated to raise the disc positioning member 32 and thereby free the disc from shaping member 29; V e a s a With particular reference to Figs. 7a and 7b, it will be noted that the lower die forming member 29 supports the peripheral region 15 ofrthe' disc throughout the entire disc periphery and as the shear member 39 approaches the complementary shearing member 28 the under side of the disc periphery is supported at all points therearound. As a result, the shearing members 39 and 28 .the disc.

.function to initially compress the periphery ofthe disc with a force sufiicient to shear the disc periphery along surface 47.

The sheared surface 47 at'the edge oflthedisc is, for all practical purposes, substantially a cylindrical surface disposed approximately perpendicular to thecentral portion 16 ofthe disc 11.' It will be noted that'the shaping surfaces 45 and 46 on the upper and lower die forming members 419 and 29,, respectively, have a .configuration such that at the moment of impact between the uppershearing member 39 with the supper surface of the .disc 11, the disc periphery makes an angle of the order of 60 with respect to the central portion 16 of This angle is designated by thesymbol a. It is important that the lower die forming member 29 rigidly support the periphery of the disc 11 at all points 'therearound as such support is necessary in order that the sheared surface 47 will be at the desired acute angle at all points around the disc periphery.

It will be understood that the die shown in Fig. 7 is for the purpose of illustrating the invention and it is contemplated that, if desired, the die members 28 and 29'may be water cooled.

Upon removal of the disc blank 11 from the die shown in Fig. 7, after the cutting edge .53 at the juncture between surfaces 47 and 48 is formed around the periphery of thedisc, the disc is placed in a reforming or reshaping press shown in Fig. 8. This reform press comprises a stationary die forming member 69 secured to a base plate 61 and an upper movable die forming member v62. An annular wear resistant ring 63 may be disposed around the edge of memberfiti, which may be replaced when undue wear is caused thereto. It will be noted that the upper and lower die forming members 62 and 60 are substantially complementary to each other and that they are so shaped that they will impart a substantially 'frustospheroidal shape to the disc 11 when .the upper member 62' is moved down against the lower member =60 with the disc disposed therebetween. Thus, substantially .all points on the surface of the disc 11 have approximately the same radius of curvature and in most instancesythis radius of curvature is of the same relative order tofmagnitude as the diameter of the disc.

After the upper die forming member 62 is retracted a plurality of ejector pins '64 may be actuated in order toremove the disc 11 from the lower die forming'member 60.

Fig. shows, in fragmentary form, the peripheral region of the completed disc 11. The completed disc is formed with the peripheral taper 14 and with a cutting edge 53 at the juncture between continuously curved surface 47 and the under or concave surface 48 of the disc 11. The angle of intersection between: surface 47 and surface 48 in the vicinity of edge 53 is designated by reference character ,8 and this angle is of the order of magnitude of 25 to 30 in one preferred form. it will be noted that the angles or and B are approximately complementary to each other, the angle [3 being slightly greater than the actual complementary angle due to the fact that some clearance must be provided between :shear members 39 and 28 and, as a result, .the surface 47 is not precisely a cylindrical surface.

Turning now to'Figs. 9 and 9a, suitable structure is illustrated to provide a slight variation in the method illustrated in the other figures and described heretofore. In Fig. 9, a pair of edge rollers 70 and 71 are suitably mounted upon driving shafts 72 and 73, respectively. The roller 70 is provided with an angled portion 74 adapted to cooperate with an angled portion 75 on roller 71. When the disc blank 11 is mounted on a vertical axis 76 parallel to the planes of rotation of rollers 70 and 71, the surfaces 74 and 75 function to simultaneously taper the peripheral region of the disc 11 and shape the peripheral region of the disc 11. Thus, the next operation following the simultaneous tapering and shaping of the disc periphery 15 need only trim or shear i5 thev peripheryofthe disc, as is performed by shearing members 29.and 28 illustrated in Figs. 7a -and.7'b.

Turning now to Figs. 11 and 12, a modified .press will be described. It will be noted that the die shown in Figs. 11 and 12, in one cycle of operation, is capable of performing all of the operations illustratedin Figs. 4 and 5. .In other words, the press shown in Fig. 11 first preforms the disc periphery in order to impart the proper shape to the edge of the disc so that the die members may shear the periphery of the disc to form the cutting edge therearound and thereafter the press functions 'to reform the disc in order to impart the desired frustospheroidal configuration thereto.

The die shown in Figs. 11 and 12 will now be described in detail. This press comprises a base or bed plate 80 which is stationary and which is provided with an annular shoulder '81 for positioning a lower shaping and shearing ring 82. Acentral shaping member 83 is concentrically disposed within the ring '82 and is provided with a suitable disc positioning stud or plug 84 for centralizing the disc blank '11. The shaping member 83'is movable upwardly from the position shown in Fig. '11 to the position shown in Fig. 12 by means of a plurality of plunger pins 85 which may be actuated by any means conventionally employed in presses.

The die shown 'in Figs. 11 and 12 also comprises. an

upper or movable portion, designated generally by reference numeral '86, comprising pressure plate 87 to which is secured a ring '88 having an upper shearing ring 89 secured thereto. The ring 88 is provided withian annular inwardly projecting shoulder 91) and concentrically positions an upper disc shaping member 91. The upper disc shaping member 91 is formed with "an annular 'out- Wardly projecting shoulder 92 adapted to cooperate with the inwardly projecting shoulder on the ring 88' in order to withdraw the shaping member 91 upon retract-ion "of the pressure plate '87. A plurality ofcompressionsprings 93 are operably' disposed between the pressure plate 87 and the upper shaping member 91and these springs 93 function to urge the shaping member 91- downwardly with-respect to the ring 88.

In the operation of the die shown in Figs. 11 and '12, assuming that the disc blank has already had its peripheral edge tapered by means such as is shown in Figs. 6 and 6a, the disc blank is placed in the press of Fig. '11 with 1 the lug-84 disposed in the center hole 12 of the disc blank. The movable press member 86 is'moved downwardly until the upper shaping member 91 strikes the periphery of the disc blank 11 and the rather sharply concavely curved peripheral region of the concave bottom surface 94 of the upper shaping member 91 cooperates with member 82 in order to preform' the disc blank 11 and thus form the periphery of the disc blank 11 .so that it makes an acute angle with the main portion of'the disc blank .11. Upon further downward advance of the movable press member 86, the upper shearing'ring 89 engages the upper peripheral surface of the disc. 11 and cooperates with the member 82 to shearthe'periphery of the disc blank 11 at an 'acute angle to ithus form the cutting edge therearound. The movable pressure member 87 descends to the position shown. in Fig. 12 and thereafter the plungers 85 are advanced upwardly in order to move the lower shaping member 83 upwardly. The disc blank 11 is thus compressed between the lower shaping member 83 and the upper shaping member 91 and the configuration of the disc blank is thus changed to the desired finished shape.

It will be noted that during the movement of the shaping member 83 upwardly the blank 11 is pulled inwardly so that the peripheral portion thereof is withdrawn from the outer periphery of the shearing member 82 and thus, not only is the central portion of the disc blank 11 reformed from a flat blank to a frustospheroidal shape, but also the peripheral portion of the blank is reformed to provide substantially less concavity around the periphery of the disc. Q

cations may be made in the present invention. without departing from the spirit or scope thereof.

. Lclaim:

1. The steps in the method of forming a sheet metal ea'rthwo'rking disc comprising forming a substantially circular flat sheet metal blank, shaping the blank substantially uniformly around the periphery thereof to PIO'.

vide a peripheral lip disposed at an acute angleto. a central'region of the blank, shearing in a direction substantially perpendicular to said central region the outermost edge of said'peripheral lip ,along a substantially cylindrical surface disposed substantially at a right angle to the central region of the blank to provide a peripheral cutting edge around the blank, and reshaping the entire blank to provide a disc having substantially the same radius of. curvature at all points thereof.

2. Thesteps in the method of forming a sheet metal earth working disc comprising forming a substantially circular-flat sheet metal blank, shaping the blank substantially uniformly aroundthe periphery thereof to provide a peripheral lip disposed at anangle of greater than .45 from a central region of the blank, shearing by a single shearing stroke of complementary die members the outermost edge of said peripheral lip along a substantially cylindrical surface disposed substantially at a right angle to the central region of the blank, saidcylindrical surface intersecting one side of the disc at an acute angle of less than 45 so as to provide a peripheral earth cutting-edge around the blank, and reshaping the entire .blank to provide a disc having substantially the same radius of curvature at all points on said one side thereof.

3. The steps in the method of forming a sheet metal earth Working disc comprising forming a substantially circular flat sheet metal blank, shaping the blank substantially uniformly around the periphery thereof to provide a tapered peripheral lip disposed at an acute angle to a central region of the blank, shearing in a direction substantially perpendicular to said central region the outermost edge of said tapered peripheral lip along a substantially cylindrical surface disposed substantially at a right angle to the central region of the blank to provide a peripheral cutting edge around the blank, and reshaping the entire blank to provide adisc having substantially the same radius of curvature at all points thereof.

a a 4. The steps in the method of forming a sheet metal earth Working disc comprising forming a substantially circular fiat'sheet metal blank, rolling the peripheral edge of the blank to provide a taper therearound, shaping the blank substantially uniformly around the tapered periphery thereof to provide a peripheral lip disposed at an acute angle to a central region of the blank, shearing in a direction substantilaly perpendicular to said central region the outermost edge of said peripheral lip along a substantially cylindrical surface disposed substantially at a right angle to the central region of the blank to provide a peripheral earth cutting edge around the blank, and reshaping the entire blank to provide a disc having substantially the same radius of curvature at all points thereof. V a

earth working disc comprising forming asubstantially circulanflat sheet metal blank, die-forming the blank substantially uniformly around the periphery thereof to provide a peripheral lip disposed at an acute angle to a central region of the blank, shearing the outermost edge of said peripheral lip along'a substantiaHy cylindrical surface disposed substantially at a right angle to the central region of the blank to provide a continuous sheared peripheral cutting edge around the blank, and die-forming the entire blank to provide a disc having substantially the same radius of curvature at all points thereof. a

I 6 The steps in the method of forming a sheet metal earth working disc comprising the steps of forming a substantially circular flat sheet metal blank, rolling the peripheral edge of the blank to provide a. taper therearound, die-forming the blank substantially uniformly around the periphery thereof to provide a peripheral lip disposed at an acute angle to a central region of the blank, shearing the outermost edge of said peripheral lip along a substantially cylindrical surface disposed substantially at a right angle to the central region of the blank to provide a continuous sheared peripheral earth cutting edge around the blank, and die-forming the entire blank to provide a disc having substantially the same radius of curvature at all points thereof.

7. The steps in the method of forming a sheet metal earth working disc comprising the steps of forming a substantially circular flat sheet metal blank, rolling the blank substantially uniformly around the periphery thereof to provide a tapered peripheral lip disposed at an acute angle to a central region of the blank, shearing in a direction substantially perpendicular to said central region the outermost edge of said peripheral lip along a substantially cylindrical surface disposed substantially at a right angle to thecentral region of the blank to provide a peripheral earth cutting edge around the blank, and die-forming the entire blank to provide a disc having substantially the same radius of curvature at all points thereof. V

8. The steps in the method of forming a sheet metal earth working disc comprising forming a substantially circular flat sheet metal blank, shaping the blank substantially uniformly around the periphery thereof to provide a peripheral lip disposed at an acute angle of the order of 60 with reference to a central region of the blank, shearing in a direction substantially perpendicular to said central region the outermost edge of said peripheral lip along a substantially cylindrical surface disposed substantially at a right angle to the central region of the blank to provide a peripheral cutting edge around the blank, and reshaping the entire blank to provide a disc having substantially the same radius of curvature at all points thereof.

References Cited in the file of this patent UNITED STATES PATENTS Ingersoll Apr. 5, 1955 

